In general, an airbag mounted in a passenger seat includes an airbag module installed in a crash pad. When a vehicle collision occurs, the airbag is deployed to absorb a shock transmitted to a passenger, while an airbag door is opened.
The crash pad has an invisible airbag deployment part installed therein. The invisible airbag deployment part is integrated with the crash pad in order to improve an appearance of the crash pad, formed in such a manner that an airbag deployment line is not seen from outside, and has a skin deployment part formed in a skin layer such that a panel can be easily opened when the airbag deployment part is opened.
The airbag deployment line set in the airbag deployment part has a small thickness such that a weak portion is artificially formed in the crash pad. Thus, when the airbag is deployed, the airbag is opened along the airbag deployment line with the small thickness. In general, the invisible airbag deployment part may be formed in the small thickness along the airbag deployment line through injection molding, or manufactured by secondarily forming a minute groove using laser beams after injection molding of the crash pad.
FIG. 1 is a cross-sectional view illustrating a hinge structure for a deployment unit of a passenger seat airbag according to the related art. As illustrated in FIG. 1, a crash pad 1 is installed in front of a passenger seat in a vehicle body, and an airbag module 2 is disposed inside the crash pad 1 so as to be separated from the crash pad 1.
The airbag module 2 serves to deploy the airbag in case of a vehicle collision. As illustrated in FIG. 1, an airbag deployment part 10 having a hinge part 11 is installed on the inner surface of the crash pad 1 facing the airbag module 2.
The airbag deployment part 10 is typically welded to the inner surface of the crash pad 1, and an end of the airbag deployment part 10 in the opposite side of the hinge part 11 is cut. Thus, when the airbag is deployed, the airbag deployment part 10 is opened while being turned in the outward direction with respect to the hinge part 11 set to the center of rotation.
In the structure illustrated in FIG. 1, however, the entire airbag deployment part 10 is made of a single material, and applied to an airbag having a relatively low explosion pressure, like a depowered airbag used in Korea or Europe. Thus, if the airbag deployment part 10 is applied to an advanced airbag having a relatively high s explosion pressure and used in the US, the airbag deployment part 10 may not be normally opened or the hinge part may be damaged, when the airbag is deployed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.